A superjunction device, which often is also referred to as compensation device, includes a drift region with at least one region of a first doping type (conductivity type) and at least one region of a second doping type (conductivity type) complementary to the first doping type. In some publications, the at least one region of the first doping type is referred to as drift region and the at least one region of the second doping type is referred to as compensation region.
A superjunction device can be operated in an on-state and an off-state. The on-state is an operation mode in which a current can flow in a current flow direction through the first doping type region. The off-state is an operation mode in which a pn-junction between the at least one first doping type region and the at least one second doping type region is reverse biased so that a space charge region (depletion region) expands in each of these doped regions in directions that are substantially perpendicular to the current flow direction.
A voltage blocking capability of a superjunction device is, inter alia, dependent on how well the amount of first type doping atoms in the first doping type region is adapted to the amount of second type doping atoms in the second doping type region. More precisely, the voltage blocking capability is dependent on how well the amount of first type doping atoms is adapted to the amount of second type doping atoms at each position in the current flow direction of the drift region. One device may include planes (extending perpendicular to the current flow direction) of the drift region where the amount of first type doping atoms and the amount of second type doping atoms is completely balanced, positions where the amount of first type doping atoms exceeds the amount of second type doping atoms, and/or positions where the amount of second type doping atoms exceeds the amount of first type doping atoms. However, in each of these cases it is desirable to exactly control the amount of first type and second type doping atoms introduced into the drift region during a manufacturing process.